tuboexec: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/tuboexec - from package: tubo

You may install the required package with command yum install {package}

Error in other languages:
tuboexec: bevel nie gevind nie
tuboexec: comandă negăsită
tuboexec: comando não encontrado
tuboexec: commande introuvable
tuboexec: command not found
tuboexec: käsku ei ole
tuboexec: không tìm thấy lệnh
tuboexec: komanda nerasta
tuboexec: Kommando nicht gefunden.
tuboexec: kommandot finns inte
tuboexec: komut yok
tuboexec: nie znaleziono polecenia
tuboexec: níor aimsíodh an t-ordú
tuboexec: no se encontró la orden
tuboexec: no s'ha trobat l'ordre
tuboexec: opdracht niet gevonden
tuboexec: parancs nem található
tuboexec: perintah tidak ditemukan
tuboexec: príkaz nenájdený
tuboexec: příkaz nenalezen
tuboexec: команда не найдена
tuboexec: командата не е открита
tuboexec: 命令找不到
tuboexec: コマンドが見つかりません